Baldur's Gate 3 is packed to the brim with secrets, but after playing the game for 2,000 hours, you'd expect to have uncovered most of them. It's also spent years patching up the biggest bugs and exploits, removing a variety of interesting glitches that players could use to their advantage. Even so, it's still possible to uncover surprises, and one player just realized how to take advantage of an odd mechanical quirk.
Reddit user Acceptable_Account_2 shared their discovery of a Shadowheart weapon duplication glitch, which they refer to as one of the "dumb tricks" that are possible in-game. After casting invoke duplicity, Shadowheart can disarm her illusory copy to duplicate her equipped weapon. Acceptable_Account_2 gained a second 
Spellsparkler out of this discovery, but notes that using it for monetary gain might not be worth the hassle.
Acceptable_Account_2 isn't the only player to have unlocked this Baldur's Gate 3 secret, and lazyefiris shares an even more efficient variation for PC players. It's a little trickier, but with the right timing, illusory copies of weapons and gear can simply be dragged into the character's inventory.
Other players are coming up with plenty of valid uses...
